JPH0432769A - Pulse generating device for detecting rotating speed of motor - Google Patents

Abstract

PURPOSE:To improve the accuracy of rotating speed detection by outputting one pulse on every 1/12 rotation of a motor and counting the pulse. CONSTITUTION:Each of Hall elements 9 - 11 provided to the stator of the motor at 120 deg. machine angle intervals outputs a voltage signal in a nearly sine wave state. Then a circuit 30 outputs an in-phase logic signal 13a on inputting the signal E1 from the element 9 and a logic signal 30a which advances in phase by an electric angle of pi/2 radian on inputting the logic signal 13a. Similarly, a circuit 31 outputs logic signals 14a and 31a in response to the input of the element 10 and a circuit 32 outputs logic signals 15a and 32a in response to the input of the element 11. Then a logical arithmetic circuit 37 outputs one pulse on every 1/12 rotation of the rotor by using the logic signals 13a - 15a, and 30a - 32a. Thus, one pulse is outputted on every 1/12 rotation of the motor, so the pulse is counted to detect the rotating speed of the motor. A 1/12 rotation is made when the absolute value of an error in rotating speed detection is maximum and the speed detection is accurately performed even when the rotating speed is slow, not to mention a case where the rotating speed is fast.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is directed to a pulse generator used in a device for detecting the rotational speed of a motor having a four-pole rotor, and in particular to improving the accuracy of two-rotation speed detection. This invention relates to a pulse generator capable of

[Conventional technology]

Figure 4 is a block diagram of the rotation speed detection device 3 of the motor 4I2 using a conventional pulse generator.
consists of a four-pole rotor 2a and a stator 2b provided with one Hall element 4, and the Hall element 4 is connected to a DC power supply 5 by a series circuit consisting of this element 4, resistor B, and R6. When the rotor 2a rotates with a bias current flowing through the element 4 due to the W connection between the element 4 and the reference potential 6.

A voltage signal 4a corresponding to the magnetic flux passing through the element 4 due to the magnetic poles of the rotor 2m is generated, and in this case, the voltage E exhibited by the signal 4a is as shown in FIG. The related parts are configured to change in a substantially sinusoidal manner according to the rotation angle θ of 2a. Then, again, the fourth
7 in the diagram.

When a signal 4m driven by a DC power supply 8 having a voltage value V and outputted by the element 4 is input, the polarity of this signal!
! ! This is a comparator that outputs a binary signal 7m in which the output voltage value V as a signal value changes to Vl or almost zero volts depending on the signal value.In this case, as shown in FIG. When it comes to gender, V=V,
Then, when the signal 4a becomes negative polarity, the signal 7m becomes VlQ.
Since the output voltage value V of the comparator 7 changes synchronously with the rotation of the motor 2 as shown in FIG. The value signal 71 is output as a pulse train signal. Therefore, in FIG. 4, it can be said that the above-mentioned parts except the motor 2 constitute the pulse generator 1. Reference numeral 81 denotes a counter to which the signal 7a is input, counts pulses per unit time in the signal 7a, and outputs a rotational speed signal 81a representing the rotational speed N of the motor 2 based on the counting result, as described above. The rotational speed detection device 3 includes this counter 81 and the pulse generator N1, and the number of rotation speeds is 411! has been completed.

[Conspiracy that invention attempts to solve]

Since the rotational speed detection length M3 is configured as described above, it is clear that the rotational speed N of the motor 2 can be known from the signal 81a, but in this case.

As shown in Figure 5, signal 7 a dp
Since two pulses appear per one rotation of the motor 2, K is ±0 at the maximum of the rotation speed N1 represented by the one rotation speed signal 81a.
．． This includes an error ΔN of 5 rotations. That is, when the above-mentioned pulse generator 1 is configured with a rotational speed detection length [3] using this device 1, the absolute value of ΔN becomes 0.5 rotations at maximum, so the detection accuracy of the speed N is said to be very poor. There is a problem.

(Uninvented) The purpose is to generate one rotation F of the motor 2 using a pulse generator.
The objective is to improve the accuracy of rotational speed detection by obtaining 12 pulses per rotation.

[Means for solving confusing problems]

In order to achieve the above object, two motors are arranged on a stator of a motor having a four-pole rotor at an interval of 120 mechanical angles, and as the rotor rotates, each of them has a substantially sinusoidal waveform. first to third Hall elements that output a voltage signal, and a first logic input with a first signal as the voltage signal outputted by the first Hall element marked * and in phase with the S'0 period first signal. 1C for the signal and this first logic signal
a first circuit that outputs a second logic signal whose phase is advanced by an electrical angle of /2 radians; A second circuit outputs a third logic signal that is in phase with the third logic signal and a fourth logic signal that is delayed in phase by an electrical angle of π/2 radians with respect to the third logic signal, and the third Hall element is configured to output an output signal. A fifth logic signal in which the third signal as the voltage signal is manually input and has an opposite phase with respect to the third signal, and a sixth logic whose phase is advanced by an electrical angle of π/2 radians with respect to the fifth logic signal. comprising a third circuit that outputs a signal and a logic operation circuit that outputs one pulse every 1/12 rotation of the # distribution rotor using the first to sixth logic signals of the four models;
Each of the first to sixth logic signals is a binary signal having both logic values of 1 and 0.

The first and third logic signals are signals whose logic value becomes 1 when the corresponding first or second signal has positive polarity, and the fifth logic signal has a logic value of 1 when the third signal has positive polarity. The pulse generator for detecting the rotational speed of the motor is configured so that the logical value becomes O when .

[Effect]

With the above configuration, every 1/12 rotation of the motor
'r1 pulses are output from the logic operation circuit, so
If the rotational speed of the motor is detected by counting the pulses output by this arithmetic circuit, the absolute value of the rotational speed detection error ΔN mentioned above will be (1/12) rotation at the maximum.
Therefore, of course when the 1 rotation speed N is high,
Even when the speed N is slow, the rotational speed of the motor can be detected with high accuracy.

〔Example〕

FIG. 1 is a block diagram of one embodiment of the present invention. In the two figures, the same parts as in FIG. 4 are given the same reference numerals as in the fourth section.

In FIG. 1, r, 9, 10, 11 are arranged at mechanical angle intervals of 20 degrees, and the stator 12bcl of the motor 412 having a four-pole rotor 12a, as shown in FIG.
As shown in the figure, the resistor is also a Hall element which is connected in series with R7 between the potential sources 5 and 6 to allow the noise current fiI to flow.

In this case, when the rotor 121 rotates with a current flowing through these elements 9 to 11, similarly to the Hall element 4 described above, the rotation angle θ of the rotor 12a becomes 2.
A voltage signal E, .E, which changes in an approximate sine wave shape as a periodic function of the rotation angle θ according to the rotation angle θ, and changes by two periods of the approximate sine wave each time the rotor 12a rotates once.
The related parts are configured to output , E.

13, 14, and 15 are all driven by a DC power source 8VC having a voltage value vl, and have voltage signals E, ,
E, , E, are all comparators, and among these comparators 13 to 15, the red comparators 13 and 14 input the input signal ratio, E2. It operates in the same way as comparator 7 for signals E, ,
B.

When is positive polarity, the signal value becomes V, and the signal E, , E
.

When the polarity of
It performs a binary signal output operation similar to the comparator 7 for the input signal E, but when the signal E1 is positive polarity, the signal value is approximately O volts, and when the voltage E is negative polarity, the signal value is V.
, ic are output. Thereafter, the binary signals 13a and 141 are converted into corresponding input signals E3. There is also a signal whose phase is the same as that of the crow. Binary signal 15a is input signal E.

It is sometimes called a signal whose phase is opposite to that of ℃.

16 receives the signal E, amplifies this E, and outputs a voltage signal 1611 whose phase is opposite to E.
/U differential amplifier, 17.18 respectively signal E,
, E, is input and E, , E, is amplified to become E,
, E, both are differential amplifiers with 5f outputting voltage signals 17al and 181 in phase, 19.20.2
1 are voltage signals 19a, 20a whose phases are advanced by π/2 radia 7 with respect to the signals 16al, 17al, and 1111 by differentiating the signals 16al, 17a, and 18a, respectively.
, 21a are all differentiators, and 23
゜24.25 is driven by a DC power supply 8 having three values vl and a DC power supply 26 having a voltage value -vl, and has a non-inverting input terminal connected to the potential source 6, and further has an inverting input terminal. Differentiator output signals 19a, 20m,
21! -m27a, 2 of the resistors 27, 28, 29 to which l is input and whose output terminals all have the same resistance value.
8a, 29a are connected to VC and the potential applied to the 1 inverting input terminal is lower than the potential of the potential source 6. Both are comparators that output a voltage of one point higher than the potential to the output terminal. D.
D, , D, each other end 2 of resistor 27゜28.29
7b, 28b, 29b and the potential source 6 as shown, and in FIG. Since they are configured and connected as shown in FIG. Voltage 30a.

31a, 32i1 become equal to V, and when a voltage of -V1 is output to the output terminals of the comparators 23 to 25, the voltages 30a, 31al and 32m become approximately 0 volts.

Now, since each part in Fig. 1 is constructed as described above, the voltage of the main parts in Fig. 1 changes as shown in Fig. 3 as Moda! rotates 20 times. ,
From this tl/I, Figure 3, the binary signals 13a*14a, 15! outputted by each of the combiners 413-15! l is a signal whose binary values change periodically with respect to the rotation angle θ of the motor 120, and the voltage at each of the other ends 27b to 29b of the resistor is V, which is approximately 0. It is clear that this is a binary signal that has a binary value with volts and that this binary value changes periodically with respect to the rotation angle #.

Furthermore, from FIG. 3, the binary signal 301 is changed to the binary signal 131 [
On the other hand, it is clear that the signal is shifted in phase by an electrical angle of π/2 radians. Then, again, the third
From the figure, the binary signal 311 is π with respect to the binary signal 14mvc.
It is clear that the phase of the binary signal 32a is delayed by an electrical angle of /2 radians, and that the binary signal 32a is a signal whose phase is advanced by an electrical angle of π/2 radians relative to the binary signal 15. Therefore, in FIG.

The comparators 13 and 23, the amplifier 16, the differentiator 19, the resistor 27, the diode DI, and the power supplies 8 and 26 input the voltage signal E1 output from the Hall element 9, and a signal 13a that is in phase with this E. A signal 30 whose phase is advanced by an electrical angle of π/2 radians with respect to this signal 13aIC.
The comparators 14 and 24, the amplifier 17, the differentiator 20, the resistor 28, and the diode D! and power supplies 8 and 26
Then, the voltage signal Bt output from the Hall element IO is input and this E! The signal 141 in phase with this signal 1
It can be said that the second circuit 31 is configured to output a signal 31m whose phase is delayed by an electrical angle of 1c/2 radian with respect to the signal 4a. And then again.

In FIG. 1, comparators 15 and 25, amplifier 18, differentiator 21, resistor 29, diode D, and power supplies 8 and 26 connect voltage signal E output by Hall element 11.
1 is input and the signal 151 has an opposite phase with respect to this Espc.
It can be said that a third circuit 32 is configured to output a signal 321 whose phase is advanced by an electrical angle of π/2 radians with respect to this signal 151.

In FIG. 1, 33 outputs a binary signal 33a having an H level signal value only when signals 13a and 31a are input as meat input signals and one of the meat input signals exhibits a signal value of ■. The exclusive OR gate 34 receives the signals 15a and 30B as meat input signals, and one of the meat input signals has a signal value v1.
The binary signal 34 has an H level signal value only when
The exclusive OR gate 35 outputs an H level signal only when the signals 1411 and 32m are input as meat input signals and one of the meat input signals exhibits a signal value v1. 36 is an exclusive OR gate configured to output a binary signal 35m having a signal 33a.
, 34&.35m are input, and when at least one of these three input signals has a signal value of H level, the OR gate outputs a binary signal 36a whose signal value becomes H level. Then, 37 is convenient 4
A logic operation circuit consisting of logic operation gates 33, 34, 35 and 36, 38 is a pulse generator as an embodiment of the present invention consisting of the various parts shown in FIG.
3a, 34a* 35a, 36at! Both are signals having signal values of both H and L levels.

In the pulse generator ft38, each part including the logic operation circuit 37 is configured as described above, so that the gates 33 to 3
Each of the output signals 338 to 35 of the gate 35 becomes a pulse train signal whose pulse peak value is H level as shown in FIG. 3, and the output signal 36m of the gate 36 also becomes a pulse train signal as shown in FIG. Therefore, one pulse 36a1 will appear in the signal 36a for every 1/12 rotation of the motor 12. Therefore.

The above-mentioned 37 corresponds to signals 131 to 151 and signals 30a to 32.
It can be said that it is a logic operation circuit that outputs one pulse 36al every 1/12 rotation of the motor rotor 12a using

In the pulse generator 38, the pulse 3611 is output from the gate 36 as described above, so that the generated snow making 3
8 is used in place of the pulse generator fl shown in FIG. 4 to constitute a rotation speed detection device together with the counter 81, the true motor speed N of the rotation speed of the motor 412 represented by the rotation speed signal 81a shown in FIG. The absolute value of the error ΔN for the maximum value is (1
/12) rotation, so depending on the rotation speed signal 811, the absolute value of the error ΔN is at most 0.5 rotations regardless of the slow speed N. When using the conventional pulse generator 1 - comparison Therefore, the rotation speed of the motor can be detected with high accuracy.

〔Effect of the invention〕

As described above, in the present invention, the motors are arranged at mechanical angle intervals of 120 degrees on the stator of a motor having a four-pole rotor, and as the rotor rotates, each of them generates a substantially sinusoidal voltage signal. first to third Hall elements that output,
A first signal as the voltage signal output by the first Hall element is input, and a first logic signal that is in phase with the first signal and a phase of an electrical angle of π/2 radian with respect to the first logic signal. A first circuit that outputs a second logic signal that is advanced, and a third circuit that is inputted with a second signal as the voltage signal outputted by the second Hall element and that is in phase with the second signal in parentheses.
A second logic signal outputting a fourth logic signal whose phase is delayed by an electrical angle of π/2 radians between the logic signal and this fa3 logic logic signal port.
A circuit, a third signal as the voltage signal outputted by the third Hall element is inputted, a fifth logic signal having an opposite phase with respect to the third signal, and a fifth logic signal of π/2 radian with respect to the fifth logic signal. a third circuit that outputs a sixth logic signal whose phase is advanced by an electrical angle; and a logic operation circuit that outputs one pulse every 1/12 rotation of the rotor using the first to sixth logic signals. The first to sixth logic signals are all binary signals having both logic values of l and 00, and the first and third logic signals are such that the corresponding first or second signal is of positive polarity. The pulse generator for detecting the rotational speed of the motor is configured such that the fifth logic signal is a signal whose logic value becomes 1 when the third signal has positive polarity, and the logic value becomes 0 when the third signal is positive. did.

Therefore, if configured as above, 1/12 of the motor
One pulse is output from the logic operation circuit for each rotation, so if this operation circuit counts the output pulses and detects the rotation speed of the motor, the absolute value of the rotation speed detection error ΔN mentioned above will be The maximum rotation speed is (1/12), and therefore, one advantage of the present invention is that the rotation speed of the motor can be detected with high precision not only when the rotation speed N is high but also when the speed N is slow. .

[Brief explanation of drawings]

Fig. 1 is a configuration diagram of an embodiment of the present invention, Fig. 2 is an explanatory diagram of the arrangement of three Hall elements shown in Fig. 1, and Fig. 3 is a change mode of signals of the main parts in Fig. 1. Explanatory diagram. Figure 4 is a configuration diagram of a conventional pulse generator, and Figure 5 is a diagram of a conventional pulse generator.
FIG. 2 is an explanatory diagram of changes in signals of important parts in the figure. l, 38... Hals generation equipment! , 2.12・
·····motor. 2a, 12a--Rotor, 2b, 12b...
... Stator, 9... Hall element (first Hall element)
, 10...Hall element (second Hall element)
, 11...Ball element (third Hall element), 1
3a-...Binary signal (first logic signal). 14 Toni value signal (third logic signal), 15a...
...Binary signal (5th logic signal), 3o...1st
Circuit, 30a output voltage (binary signal, second logic signal), 3
1... Second circuit, 31 To... Output voltage (binary signal, fourth logic signal), 32, Song, Third circuit, 32a
・-Bending voltage (binary signal, 6th logic signal), 36a
x...Pulse, 37...Logic operation circuit, Equalization...Voltage signal (first signal). El... Voltage signal (second signal), E8...
・Voltage signal I・-1, / sticky note paper diagram

Claims (1)

[Claims] 1) First to third motors arranged at mechanical angle intervals of 120 degrees on the stator of a motor having a four-pole rotor, and each of which outputs a substantially sinusoidal voltage signal as the rotor rotates. A Hall element, a first logic signal which is input with a first signal as the voltage signal outputted by the first Hall element and which is in phase with the first signal, and a π/2 radian with respect to the first logic signal. a first circuit that outputs a second logic signal whose phase is advanced by an electrical angle of a second circuit that outputs a third logic signal and a fourth logic signal whose phase is delayed by an electrical angle of π/2 radians with respect to the third logic signal; A fifth logic signal inputted with a third signal and outputting a fifth logic signal having an opposite phase with respect to the third signal and a sixth logic signal having a phase lead of π/2 radian electrical angle with respect to the fifth logic signal. 3 circuits, and a logic operation circuit that outputs one pulse every 1/12 rotation of the rotor using the first to sixth logic signals,
The first to sixth logic signals are all binary signals having both logic values of 1 and 0, and the first and third logic signals are such that the corresponding first or second signal is of positive polarity. The fifth logic signal is a signal whose logic value becomes 0 when the third signal has the positive polarity. Generator.